Compounds in the form of [2-(4-methoxycarbonyl-phenoxy)-ethyl]-trimethylammonium and [2-(4-ethoxycarbonyl-phenoxy)-ethyl]-trimethylammonium are known (see UK Patent No. 919126).
A method for producing the aforementioned compounds in the case the quaternary ammonium group is a trimethylammonium group is described in which a phenol derivative is reacted with ethane dibromide in the presence of sodium metal, further reacted with dimethylamine, and treated with methyl iodide (see UK Patent No. 919126). In addition, a method for introducing a dimethylaminoethyl group, which is able to serve as a precursor of a quaternary ammonium group, is described in which a phenol derivative is reacted with 2-dimethylaminoethyl chloride in the presence of sodium metal (see German Patent No. 905738). Moreover, a method for introducing a dimethylaminoethyl group is described in which a phenol derivative is reacted with 2-dimethylaminoethyl chloride in the presence of a metal alcoholate (see M. B. Moore, J. Amer. Chem. Soc., 78:5633-5636 (1956)).
However, among the aforementioned compounds, a compound is not known which has a carboxyl group or sulfonyl group instead of an alkoxycarbonyl group in a benzene ring.
In addition, a production method has heretofore not been known for introducing a dialkylamino group, capable of serving as a precursor of a quaternary ammonium compound having a carboxyl group or sulfonyl group, at high yield by reacting with a sulfonic acid ester derivative in a certain specific solvent.
In addition, it has heretofore been completely unknown that a quaternary ammonium compound of the present invention has superior safety and demonstrates extremely superior effects as a cerebrovascular disease therapeutic agent and heart disease therapeutic agent.